Web applications are prime targets for attackers because they often handle sensitive data and provide direct access to backend systems. Understanding common attack vectors is essential for developers, security professionals, and anyone responsible for safeguarding applications.

Most web application attacks fall into these five categories:

1. Information Disclosure

When an application or server unintentionally leaks sensitive information, attackers can use it to plan further exploits.

Examples:

  • Server banners revealing software versions
  • Path disclosure in error messages
  • Sensitive data exposure (API keys, credentials)

Why it matters: Even small leaks can give attackers the clues they need to compromise your system.

2. Injection

One of the most prevalent and dangerous attack types. Injection flaws occur when untrusted data is sent to an interpreter as part of a command or query.

Examples:

  • SQL Injection — manipulating database queries
  • Command Injection — executing OS commands
  • Code Injection — injecting executable code
  • Path Traversal — accessing unauthorized files
  • XML Injection — tampering with XML data

Impact: Can lead to data breaches, system compromise, or full application takeover.

3. Authentication

Authentication ensures users are who they claim to be. Weaknesses here can allow attackers to impersonate legitimate users.

Examples:

  • Session leakage
  • Non-encrypted passwords
  • Session fixation (session ID doesn't change after login/logout)
  • Session hijacking

Tip: Always enforce strong password policies, use HTTPS, and implement secure session management.

4. Authorization

Authorization determines what an authenticated user can do. Misconfigurations here often lead to privilege escalation.

Examples:

  • Missing or misconfigured access controls
  • Hidden fields that can be manipulated
  • Application logic flaws (e.g., skipping steps in workflows)

Best practice: Apply the principle of least privilege and test for broken access controls.

5. Misconfiguration

Improper setup or maintenance creates easy entry points for attackers.

Examples:

  • Unpatched servers
  • Default credentials
  • Unnecessary open ports
  • Incorrect error handling revealing stack traces

Solution: Regularly review configurations, patch systems, and disable unused services.

Final Thoughts

These categories align closely with the https://owasp.org/Top10/, a must-read for anyone in application security. By understanding these attack vectors, you can design, build, and maintain more secure web applications.

Reference: The Art of Hacking Video Courses and Live Training — Omar Santos